Electrical pulse

I have most of the bugs sorted out on my 5.7 swap into my 71 Demon but now that I have the charging system working all of the lights and the electric fuel pump have a pulse to them. With a digital volt meter at the battery it ranges from 14.50 to 15.1 volts. The voltage on the meter will stop changing and go steady for a couple of seconds then go back to fluctuating but the lights will still pulse and the fuel gauge continues to pulse as well. This wasn't happening when the charging system wasn't working and the engine running before I sorted out the charging system. I used the front cover/assemblies for a 2009 Challenger on the Ram 5.7 engine. The alternator is a rebuilt unit from Autozone ( I know...that's where my problem started lol) and the regulator/wiring harness is from Quick Start. They said to set the resistance at 1.750 ohms and that will be preset for 14.1 volts. At that setting it's well over 15 volts to the battery. I have it set to 1.850 ohms for the 14.5+ volts ( I need to dial the voltage back a little more). This is my first swap like this but not my first rodeo so the normal things to check are all good. Anyone ever run into this before?